Centrifugal auto-priming pump

ABSTRACT

A centrifugal auto-priming pump comprising a hollow casing, a shaft extending within the casing and a sealing plate dividing the casing to define a pressure chamber. One end of the shaft extends outward of the casing and the other end is enlarged and hollow to provide an opening congruent with a central fluid inlet to the casing. A plurality of passages in the shaft, connect the fluid inlet to within the casing. Conduits arranged in cycloidal paths connect the passages to the pressure chamber through the sealing plate. The conduits extend into the pressure chamber and are provided with flared ends to act as impellers. Seals around the sealing plate prevent the fluid being pumped from coming into contact with bearings supporting the rotatable shaft.

United States Patent 1191 Jackson 1 Aug. 19, 1975 1 1 CENTRIFUGAL AUTO-PRIMING PUMP 22 Filed: Apr. 30, 1974 21 App1.No.:465,566

553.368 12/1956 Italy ..415/88 Primary E.\-aminerI-Ienry F. Raduazo Attorney, Agent, or F irmW. Britton Moore [5 7] ABSTRACT A centrifugal auto-priming pump comprising a hollow casing, a shaft extending within the casing and a sealing plate dividing the casing to define a pressure chamber. One end of the shaft extends outward of the casing and the other end is enlarged and hollow to provide an openingcongruen't with a central fluid inlet to the casing. A plurality of passages in the shaft, connect the fluid inlet to within the casing. Conduits arranged in cycloidal paths connect the passages to the pressure chamber through the sealing plate. The conduits extend into the pressure chamber and are provided with flared ends to act as impellers. Seals around the sealing plate prevent the fluid being pumped from coming into contact with bearings supporting the rotatable shaft.

3 Claims, 2 Drawing Figures [52] US. CL. 415/88 [51] Int. CI. F041) l/12 [58] Field of Search 415/88, 170 A, 89; 417/173 A [56] 7 References Cited UNITED STATES PATENTS 450,491 4/1891 Nicholas et a1. 415/88 1,007,266 10/1911 Burrel] 1 1 v. 415/88 1.074.043 9/1913 Breuer v 1 415/88 2,333 l50 11/1943 Bowen 415/173 A 1543.242 2/1951 Kent et a1. 415/88 3,218,982 11/1965 Wigton 415/89 3.809.491 5/1974 Banyai 415/88 FOREIGN PATENTS OR APPLICATIONS 655897 8/1951 United Kingdom 415/88 CENTRIFUGAL AUTOJPRIMING PUMP This invention relates to pumps and more particularly to centrifugal auto-priming pumps.

Prior art centrifugal pumps have generally been constructed utilizing an impeller rotating inside a casing having a central opening for admitting a fluid and a radially displaced opening for discharging the fluid. Such pumps are subject to cavitation, are inefficient and suffer from early failure due to wear and deterioration of internal components exposed to the fluid being pumped. More recently, centrifugal pumps have been constructed utilizing a rotating casing to impart energy to a fluid entering a central opening at one end of the casing and then discharging the fluid through a central opening at the opposite end of the casing. This latter construction eliminates many of the problems associated with the use of the earlier type pumps, but does not provide the efficiency available from using impeller action and radial discharge.

It is an object of the present invention to provide a centrifugal pump of simple, economical and durable design.

A further object of this invention is to provide a centrifugal pump capable of pumping a wide range of liquids and liquid slurries.

A still further object of this invention is to provide a centrifugal pump which is inexpensive and easily maintained and has a minimum of moving parts.

A still further object of this invention is to provide a centrifugal pump which develops sufficient pressure differentials to be auto-priming.

Accordingly. the present invention provides a centrifugal pump having a centrally located intake opening and a plurality of cycloidially shaped conduits leading from the intake to a pressure chamber. A plate attached to a central shaft contains a plurality of openings for receiving the discharge ends of the conduits for providing rigidity to the assembly to prevent distortion of the conduits during rotation. The plate further separates the fluid being pumped from the main seals and bearings. The conduits are provided with flared lips on the discharge ends which act as impellers to increase the efficiency of the pump. A discharge opening is located radially from the pressure chamber.

The foregoing and other objects, features and advantages of the invention will be apparent from the following description of the invention, as illustrated in the accompanying drawings wherein:

FIG. 1 is a partial vertical section of an embodiment of the invention showing the arrangement of internal parts and outer casing; and

FIG. 2 is a partial sectional view of the pump of FIG. 1 taken along lines 2-2.

Referring now to FIG. 1, the pump includes a casing having an upper section 12 and a lower section 14, the two sections being joined together by a plurality of circumferentially arranged bolt and nut assemblies 16. Section 12 is provided with an intake port 17 in an elongated portion 18 which may be adapted externally, such as by threading, for receiving a fluid supply line and which portion includes an annular recessed area 20 adapted to receive a bearing 22. Section 14 is provided with an opening 24 in an elongated portion 26 which includes an annular recessed area 28 adapted to receive a bearing 30.

A shaft 32 extends through opening 24 and is attached to an enlarged section 36 into which defines a central opening 38 congruent with port 17 defined by step 34. A plurality of passages 40 extend from opening 38 to surface 42. Each of the passages 40 is provided with a stepped portion 44 for receiving a conduit 46 having thesame inside diameter as passages 40. The absence of discontinuities between opening 17 and conduits 46 minimizes turbulence in the fluid flow path. An annular bearing 47 provides additional sup port for shaft 32.

Conduits 46 follow a cycloidal path through openings 48 in sealing plate 50 and into pressure chamber 52. Conduits 46 are provided with flared lips 54 at their discharge ends to increase the efficiency of the conduits acting as impellers.

Sealing plate 50 is an annular plate which, in conjunction with casing sections 12 and 14, defines pressure chamber 52. A seal 56 at the outer periphery of plate 50 and a seal 58 around a central opening in plate 50 prevent leakage of fluid from chamber 52 and thus away from bearings 47, 22 and 30. Seals 56 and 58, preferably of teflon or nylon, may, be attached to plate 50 by means of a plurality of rivets 60 and 62, respectively. As will be apparent, plate 50 is constrained in position only by being fixedly attached to conduits 46.

A spring 64 acting between a step 66 on shaft 32 and a stop 68 on bearing 30 pressures shaft 32 towards intake port 17 to minimize pressure and resultant wear of seal 58.

A discharge port 70, shown clearly in FIG. 2, is located at the perimeter of pressure chamber 52 for passage of fluid from the chamber.

In operation, shaft 32 is rotated in a clockwise direction, as indicated by the arrow :in FIG. 2, causing a flow from the intake port 17 toward the discharge port 70, due to the pressure differential created by rotation of the cycloidal shaped conduits 46. As the fluid enters pressure chamber 52, the expanded lips of the conduits act as impellers adding additional energy to the fluid and increasing the radial pressure to force the fluid out of the pressure chamber.

The conduits 46 act to create a laminar flow of the fluid thereby increasing pump efficiency. The separation of bearings from direct contact with the fluid being pumped by means of plate 50 minimizes the possibility of bearing failure. Because of its simplicity of design. the pump components can be constructed of various rigid materials thereby allowing pumping of a wide range of fluids, including those of a corrosive nature.

While the invention has been described with reference to a particular embodiment, it will be understood by those skilled in the art that the foregoing and other changes in form and detail may be made therein without departing from the spirit and scope of the invention.

What is claimed is:

l. A pump comprising a casing having a central inlet for receiving a fluent material, a radially disposed outlet for discharging said fluent material and a central opening axially aligned with and opposing said inlet; a rotor comprising a shaft located centrally within said casing. said shaft having a first portion extending through said opening without said casing and a second enlarged hollow portion congruent with said inlet, said shaft further including a plurality of passages communicating from said hollow portion to within said casing;

a sealing plate located within said casing, said plate di- 2. The pump defined in claim 1 wherein said conduits viding the space within said casing to define a pressure are provided with flared ends within said pressure chamber, and an isolation space for support bearings of chamber for acting as impellers. said rotor; and a plurality of tubular conduits connect- 3. The pump as defined in claim 1 wherein said coning said passages to said pressure chamber and passing 5 duits follow a cycloidal path from said passages to said through said sealing plate, wherein rotation of said pressure chamber.

shaft causes fluid flow from said inlet to said outlet. 

1. A pump comprising a casing having a central inlet for receiving a fluent material, a radially disposed outlet for discharging said fluent material and a central opening axially aligned with and opposing said inlet; a rotor comprising a shaft located centrally within said casing, said shaft having a first portion extending through said opening without said casing and a second enlarged hollow portion congruent with said inlet, said shaft further including a plurality of passages communicating from said hollow portion to withiN said casing; a sealing plate located within said casing, said plate dividing the space within said casing to define a pressure chamber, and an isolation space for support bearings of said rotor; and a plurality of tubular conduits connecting said passages to said pressure chamber and passing through said sealing plate, wherein rotation of said shaft causes fluid flow from said inlet to said outlet.
 2. The pump defined in claim 1 wherein said conduits are provided with flared ends within said pressure chamber for acting as impellers.
 3. The pump as defined in claim 1 wherein said conduits follow a cycloidal path from said passages to said pressure chamber. 